Circuit-control means



Feb. 9, 1926.

G. A. TAYLOR CIRCUIT CONTROL MEANS Filed y 9, 1924 I INVENTORY GEURGE fl DYLUR.

operation of the switch.

Patented Feb. 9, 1926.

PATENT OFFICE.

UNITED STATES GEORGE A. TAYLOR, OE MUNOIE, INDIANA.

Application filed May 9,

T 0 all whom it may concern:

Be it known that GEORGE A. TArLoR, a citizen of the United States, residing at 1333 East- Jackson Street, Muncie, in the county of Delaware and State of Indiana, has invented certain new and useful 11nprovements in Circuit-Control Means, of which the following is a specification.

This invention relates to circuit control devices for ovens and pertains especially to electrically heated ovens known as tireless stoves or cookers. A type of this class of ovens consists of a case or cabinet having double walls between which are packed in sulatory material, and in which said cabinet is embodied the oven or cooking well.

The food to be cooked is retained in the oven, there being a cover member adapted to close or seal the oven. The oven is subjected to heat derived from heater elements operated by electricity, the temperature of the even being raised to a degree which may be termed the cooking temperature. For the escape of the gases generated during the cooking operation, and which gases may be designated as steam, there is usually provided a vent or discharge pipe. After the degree of heat or cooking tcn'lperature referred to will have been reached, there is no longer the need of continuing the supply of heat electrically, and it is desirable that the said electrical energy may then be dispensed with automatically.

Temperature responsive means or thermostatic switches heretofore devised are adapted to work in close connection with the gas or discharge conduit, reliance being placed upon the heat transmitted by said conduit, from fluid passing therethrough, for the Mechanisms so constructed are unsatisfactory on account of the uncertainty of the heat registered by the passing gases and on account of the impairing effect the steam and products of condens sation produce on. the switch mechanism. To overcome the above objections, and to provide a circuit control means which is simple of construction, and not liable to be come deranged, and which is reliable in operation, are the purposes of the present invention.

My invention is embodied in the new construction, combination and arrangement of parts shown in the accompanying drawings, and described in the following specification and definediin the appended claims. The

CIRCUIT-CONTROL MEANS.

1924. Serial No. 712,109.

different parts of the invention are identified by suitable characters of reference applied thereto in the drawings, in which,

Figure 1 is a front view of my improved circuit control device installed for use on an electric fireless stove of standard form.

Figure 2 is an enlarged front view of the invention, the cover plate of the easement box being broken away.

Figure 3 is a transverse vertical sectional view taken on the line 3-8 in Figure 2.

Figure 4 is a sectional plan view taken on the line et% in Figure 3.

Figure 5 is a front view of a portion of the box cover, showing the aperture provided for the switch bar handle.

The invention consists of an air tight chamber or receptacle which opens from the interior of the oven or well, an electric switch in the circuit of the heating unit of the stove, and which switch is retained nor mally closed, and a thermostatic element operable by the heat radiated from the said chamber, to open the switch.

The present embodiment of my invention is that show' for use on a tireless stove having a cooking oven about ten inches in diameter and twelve inches high. Electric wires A and B (see Figure 2), lead from a usual electric heating element contained in the stove structure. (Said heating element being not shown.) The chamber or recepta cle 1 is of air tight structure and has its inner rim or flange at sealed connection with the interior wall of the oven. The main portion of the body of the chamber is surrounded by the insulatory packing G, and the outer end or head 1 of the chamber extends beyond the external wall of the stove about one inch. The working parts of my invention are contained in a metal box or casement 2 having its back plate 8 to fit the stovewall D, the said box being supported by cap screws 3*. In proximity to the outer end of the chamber head i is a member des v ignated as a latch bar. This latch bar 5 made of thermostatic metal has its upper portion 5 of arched or curved form and is anchored at position by a bracket 6 which is secured by-bolts 7. The free portion of the latch bar-extends downwardly and occupies substantially a vertical position, as plainly shown in Figure 3. At location below the said latch bar 5 a member 8 designated as a switch bar is disposed slidingly in dielectric bushings ,9 and 10 that are supported by a bracket 11 which is bolted to the back of the easement The action of the coil spring 12 which is arranged between the bushings 10 and a cross-pin13 of the switch bar 8, is to urge the said switch bar upwardly and with the di-electric cross head 1% of the said switch bar 8 in engagement with the free end of the latch bar 5, (when the latter-is at the retracted or low temperature position). The nose 8 of the switch bar when the. latter is at the lowered position, as shown at Figure: 3, is in engagement with themetal contactstrips 16 of the terminal posts 17 and 18. A radial stud 20 which extends from the, upper portion of the cross head. 14-, performs the function of moving the latch bar 5 laterally, and disengaged from. the-said cross head, as shown by the dotted lines in Figure 3. a A-handle 21 which is secured tothe said cross pin 13, extends outside of the cover plate 2" ofvthe casement box 2.. By means of this handle the-user may manipulate the switch bar in the man ner and'for the purposehereinafter specified.

At proper location with reference to the handle bar 21 there is provided inthe cover plate 2",, a three way aperture which is of the shapeas shown in Figure 1, the upper opening being designat'edfopen, the left hand'fopening being designated as. off and the right hand opening being, designated as lock. The central portion of the aperture isdesignated as on. The. abovedes'cribed symbols'are-impressedin the cover plate for the guidance of the user.

,lVith the several parts of the invention at the relative positions shown, the circuit is closed, the switch bar 8 having been lowered to the on position by the user depressingthe handle 21. In the functioning of the device, uncer the influence of the heat transmitted by" the chamber 1, the latch bar 5 is caused to move laterally and apart from the head 14, thereby permitting the switch bar S-to.shoot-upwardly, and clear of the terminal strips 16.

My improved circuit control means of breaker, installed, has the switch bar set at the raisedioi jdotted,line position, the electric circuit thus being open. It isunderstood that the'w-ires A and B have connec tion' with the terminals-E and 18 respectively, andthat the said wires A and B extend to the terminals of the heater element (not shown) contained in the stove body.

To" close the circuit to commence cooking,

thehandle 21 is lowered, the nose 8 of the switch bar making contact with the'contact strips '16. j The latchbar 5 having. sprung into engagement with thecross head 14, the switch barvis held securely ,against movement,the circuit thus being maintained closed. \Vithfthe circuit, closed, theheat supplied to the stove soon increases the oven temperature and the cooking operation proceeds, the objectof theuse of the circuit being to raise the temperature of the contents of the oven-to the degree at which the cooking may then be continued by the inherent stored heat and well known principle of tireless cooking.

\Vith the raising of the heat to the point where steam is generated (its escape being provided for by the usual vent the chamber head will have acquired the degree of heat for which the latch bar 5 is calibrated, and which said latch bar under such effect, is caused to move; its free end slip ping apart or free from the cross head hearing plate 1462- The switch Jar 8 thus being released, is shotupwardly by the spring 12 andis retained at the raised or dotted line position by said spring, the circuit then being open accordingly.

To effect the opening or breaking of the circuit, independently of the llllQlillUStillllC means above described, the handle 2' is thrown-to the left, or oil? position, in this movement the stud20 impinging against the end of the latch bar and disengagcs it from its conta t with the cross head. This feature makes practicablefthe maintenance of the latch bar disengaged when a temporary shortened period of the maximum cooking temperature is desired. T 0 cause the switch to remain closed, regardless of the operation of the latch bar 5, the handle 21 is thrown to the right and in occupancy of the opening designated as lock. It is apparent. that with the switch bar 8 so held by the handle 21 in the;lock opening, the spring 12 is inoperative.

In the embodiment of my invention just described, the distance of'the latch bar arch 5 from'the chamber head 1, issuch that the moment of actuation of the latch bar is effective at 'the'moment when preheating will have been completed in the handling of foods comprised in the range of treatment entering I generally for domestic operations, suchas boiling, baking, steaming, roasting and stewing. In event the stove may be intended for the treatment of food not includedin the above, or in using the stove for any other purpose, then the latch bar 5, and the distance thereof from the chamher head 1 maybe modified accordingly for service specific to any spccial require ments.

The advantage of my invention is, that after the food has been prepared for cooking and" has been placed in the oven and the oven has been closed and sealed. in the usual manner by the cover element G, and the electric circuit is closed, there is no anxiety by .the user of overheating the stove, or of injury.thereofor to the food. Coincidentally'withthe generation of heat in the oven to the'degree to wliichtlie circuit breaker has been calibrated, there is the automatic opening or breaking of the circuit, and the consequent cessation of the function of the electric heater element.

To install the device, the electric wires A and B are inserted through the di-electric bushings A and B and connected to the terminals E and 18. n3 designates the electric wire which makes connection between the terminals F and 17. The casement box is then set at position against the stove wall D, the chamber head I occupying position in the opening. The box is then adjusted to the suitable height having reference to the distance desired between the arch 5 of the latch bar and the chamber head. The cap screws are then tightened and the box is accordingly secured at the position shown. The cover plate 9f is then applied to its position and may be secured by the cap screws 2 It will be observed that the opening 3" in the back plate of the easement box is of diameter slightly larger than the diameter of the chamber head 1; also, that the holes 3, for the cap screws 3 are elongated, as plainly shown in Figure 2.

hat I claim and desire to secure by Letters Patent is: v

1. In fireless stoves, the combination with a closed oven provided with a vent, and electric heating means for the oven, a chamber extending from the oven and beyond the external stove wall and having its outer end closed, a switch in the circuit, a thermostatic latch bar to normally hold the switch closed, but which is operable by the heat trans mitted from the head portion of said cham her to move the latch bar to permit the switch to open.

2..The combination with an oven having outer wall and insulatory packing therebetween; and electric heating means, a chamber head member extending from the oven and through said packing and beyond the outer wall of the stove the outer end of which said chamber is closed, a thermostatic bar actuated by the heat transn'iitted by the chamber head, a switch bar adjacent to the thern'iostatic bar and capable of being held normally at closed position by the said thermostatic bar, means to urge the switch to open position when it is released by the thermostatic bar.

3. In tireless stoves, the combination with a closed oven provided with a vent, and electricheating means for the oven, a chamber extending from the oven and beyond the external stove wall and having its outer end closed, a easement on the stove wall to en close the head of said chamber, an electric switch in said casement, a thern'iostatic bar having its base portion arched over the head of said chamber the tree portion of said her being disposed downwardly and adapted to normally hold the switch closed, but which when the chamber head becomes heated, operates to permit the switch to open.

4. In fireless stoves comprising a closed even provided with a vent, and electric heat ing means for the oven, the combination of a chamber protruded from the oven and beyond the external stove wall, an electric switch, a spring to hold the switch normally open, a thermostatic bar having its base portion arched over the cylindrical head portion of said chamber, the tree portion of said bar being disposed downwardly and adapted to engage the switch bar when the latter is deple red to closed position, and to hecome disengaged from said switch bar when the chamber head becomes heated.

In testimony whereof I atfix my signature.

GEORGE A. TAYLOR. 

